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Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ANGLESITE


ANGLESITE (Anglesit—Anglésite—јнглезит) (Beudant F.S., 1832). Named after its discovery location on the Isle of Anglesey, Wales, Great Britain.

Composition & Properties. Sulfate group – Pb[SO4], the group of baryte, orthorhombic system. Hardness 3-3.5. Density 6.3-6.4. Diamond luster to greasy one or silk one. Cleavage in two directions. Fragile. Anglesite is found in the shape of columnar crystals and grained masses. Color: white, yellowish, brownish, greenish and bluish. Transparent to translucent.

Deposits. Anglesite is usually formed in the oxidation zones of lead ore veins. It is widespread, that’s why we mention only the most typical deposits with transparent crystals. In Russia, colorless and brown crystals of anglesite are found in Transbaikalia, in Nerchinskiy Dist., Chita Region. In Great Britain, they were found at the Matlock deposit, Derbyshire; and colorless crystals – in Scotland, in the region of Leadhills. In Spain, crystals of anglesite to 10x6 cm. are known from Cartagena, Murcia. In Italy, on Sardinia, in the regions of Monteponi and Iglesias, colorless and light blue crystals of anglesite have the local name Sardinian. In Tunisia, in the region of Sïdï-Amor-Bin Sälim, they extracted crystals of anglesite up to 20x10 cm. In Morocco, at the Bou Azzer locality, they extract green crystals of anglesite available for faceting, and at the Touissit mine – crystals up to 60 cm. long. Alarge crystal of anglesite from Morocco, 55x22 cm. in size, is kept in the Museum École Nation., Paris, now. In Namibia, at the Tsumeb deposit, they find different colored transparent crystals to 20 cm. in size, from which they make faceted stones up to 90 ct. In Australia, crystals of anglesite were discovered on the Tasmania Is., in the region of Dundas, and at the Comet Maestries deposit. In the U.S.A., in Pennsylvania, lustrous anglesite crystals to 12x4 cm. were found at Phoenixville, Chestr Co. From green crystals of good quality these deposits are received faceted stones up to 2.4 ct. In Mexico, yellow crystals of anglesite up to 10 cm. long were found near to Aquiles Serdan, in the ore region of Santa Eulalia as well as at the Sierra de los Lamentos deposit of sulfur, Chihuahua State.

Synonyms. Bleiglas, Germ. | Lead glass | White lead | Vitriolic lead ore | Sardinian, after the discovery location on the Sardinia Is. | Vitriolic lead spar | Lead vitriol.

Treatment. Anglesite is of interest only for collection faceting. Colorless stones display the strong play of light because on the high level of dispersion and refraction. The weight of faceted stones is not more than 5 ct. The biggest is a yellow stone 88.7 ct. in weight in the Museum of Calgary, Canada.

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